Online sales systems, such as are used by online retailers, auction sites, and other systems, require payment mechanisms to facilitate a funds transfer to a seller of goods and services from a buyer of those goods and services. Existing sales systems typically rely on credit card companies for payment processing and management of payment systems. However, credit card systems have drawbacks. For example, credit card companies charge processing fees to sellers. Credit card companies also limit buyers to certain types of cards; this can limit the universe of potential buyers, because those buyers may not have the type of credit card accepted by the particular retailer.
More recently, online sales systems have attempted to integrate direct payment systems to perform simple money transfer tasks, thereby avoiding use of credit cards or other similar credit-based systems. In these systems, a payment mechanism allows a direct funds transfer between accounts managed by buyers and sellers. However, the existing direct payment systems have disadvantages as well. For example, these existing direct payment systems do not share data with online sales systems in real time. Rather, all information relating to a sale or other transaction is collected by the sales system, and the sale is confirmed without full information relating to whether funds are available for transfer via the direct payment system. After the sales transaction completes, the direct payment system receives the information relating to the transaction and performs the actual funds transfer. However, if funds are in fact not available in a buyer's account, the seller will have incorrectly completed the sales transaction, because in fact the seller's price could not have been paid by the buyer at the time of the sale. These transactions must be subsequently canceled, causing possible inventory restocking, scheduling, or other issues. Other direct payment systems generally require the buyer to be redirected completely away from the seller's website to perform the funds transfer transaction required by the purchase.
For these and other reasons, improvements are desirable.